Instrumented flow path hardware for aerodynamic test engines typically include vanes or blades with trenches machined into airfoil surfaces for the routing of small diameter tubing for the transmission of static pressure from sensor to transducer.
Hardware is typically fabricated from high strength metallic materials to accommodate the geometric complexity of the trenching and the increased stresses due to removal of material. The design and fabrication of test hardware requires substantial resources in terms of manpower, schedule and cost.
In addition, the presence of small diameter tubing on the surfaces of airfoils and in the flow path alters the flow of air and affects the actual pressure being measured.